Bevel end protectors are commonly used in the steel pipe industry to protect the finished ends of steel pipes and tubes. The majority of prior art end protectors comprise a sleeve-like member with means for securing that member to the outside end of the pipe.
End protectors adapted for insertion into the pipe to provide protection from therein are also familiar to the art. U.S. Pat. No. 2,196,454 discloses a thread protector for preserving both the interior and exterior threads of a pipe. The protector of that patent includes a collar-like inner shell which is expandable to tightly bear against the interior of the pipe by means of a pair of brackets arranged at each end of the shell and a bolt rotatably received by each bracket. Rotation of the bolt within the brackets effects expansion of the inner shell to that of the inner circumference of the pipe as each bracketted end is urged apart.
In U.S. Pat. No. 2,098,088 there is shown a thread protector for the interior of a pipe which includes hinging means and a hand-operated lever to open and close the hinge. After the thread protector is inserted within the pipe, the lever is pushed against the inner surface of the protector to close the hinge and secure the protector within the pipe. The protector of U.S. Pat. No. 1,715,792 includes a plurality of radially extending bolts disposed between a hub and a cylindrical inner shell. Adjustment of the bolts with respect to the hub either pushes the inner shell against, or retracts the inner shell from, the inner surface of the pipe.
The use of a wedge is disclosed in U.S. Pat. No. 2,156,221. The thread protector of that patent is adapted to accommodate a tapered wedge key. After the protector is in place within the pipe, the wedge key remains on the structure to provide the locking means. Should the pipe undergo impact or the like however, the wedge could be jarred loose and fall from the thread protector so that the thread protector may become separated from the pipe.